Blogger, a Google division, will turn the ability to update a site via FTP/SFTP on 26 March 2010: Blogger has long allowed its users to publish sites using its tools to other servers under the control of users using the ancient FTP and newer secure FTP (SFTP) protocols. (They are not the same thing, but look the same from the outside.)
This let someone use the power of the Blogger system to manage and publish posts without having to have content hosted on Blogger/Google's servers. It's not a surprise it's going away because it's tweaky thing to set up in the first place. Most people who want that kind of functionality would have moved to a self-hosted or ISP-based Movable Type or WordPress installation.
Blogger says that only 0.5 percent of sites use FTP, but that vastly more engineering resources are needed to keep the FTP system working, and that the core technology that supports this publication method will be going away shortly from Google as a whole.
